A system for collaborative viewing of a digital slide image. In an embodiment, a session is established for viewing a digital slide image by a plurality of client viewers. A leader client viewer and non-leader client viewers are identified for the session. When a command is received from the leader client viewer, the command is sent to each of the non-leader client viewers to synchronize a view of the digital slide image at the non-leader client viewers with the view of the digital slide image at the leader client viewer.